But Ellison's $600 million (or so) purchase, which is slated to close this week, is only part of the story. David Murdock, the man who sold the island to Ellison is a major businessman—and eccentric character—in his own right.

Murdock, 89, took over the company that owned fruit and vegetable producer Dole in 1985, and turned it into a moneymaker. As part of that deal he also acquired Lanai, which was at one time the world's largest pineapple plantation.

But perhaps the most interesting thing about the billionaire is his quest to live to the age of 125.

It's not just a passing interest, either. Murdock has poured some $500 million of his own money into a science center in North Carolina that's "dedicated to his conviction that plants, eaten in copious quantities and the right variety, hold the promise of optimal health and maximal life span," according to Frank Bruni's profile of him in the New York Times last year.

Murdock became obsessed with health after he lost his third wife to cancer at the age of 43.

Here are just a few of the things he does in his race to outpace death, according to Bruni's profile:

"He crams as many as 20 [fruits and vegetables], including pulverized banana peels and the ground-up rinds of oranges, into the smoothies he drinks two to three times a day, to keep his body brimming with fiber and vitamins."

"He eats plenty of seafood, egg whites, beans and nuts to compensate for his avoidance of dairy, red meat and poultry, which are consigned to a list of forbidden foods that also includes alcohol, sugar and salt."

"He tries to fit in weight lifting several times a week, and that, combined with brisk walks on a treadmill and his diet, helps keep his weight at about 140 pounds, though he has always been naturally slender, even when he ate what he pleased."

"In restaurants Murdock will push the butter dish toward the server and say, 'Take the death off the table.'"

"When he had that sore throat, he didn’t suck on a lozenge or swallow aspirin. When he has had precancerous growths removed from his face, he has passed on anesthetics. 'I just turned my brain on and said, ‘Cut!’' he said. 'Of course it hurt. But I controlled that.'"